textproduct: Rapid City

KEY MESSAGES

-Active through mid week as a series of disturbances move through the region, with severe thunderstorms possible today, more isolated Wed and Thur

-Very hot this weekend into early next week with record high temps possible and dangerous heat

DISCUSSION

(This Afternoon Through Monday) Issued at 1025 AM MDT Tue Jul 7 2026

Impulse filled westerly flow will be in place over the region through Thursday as a frontal boundary remains in place. Near daily chances for thunderstorms can be expected with severe storms possible at times, best chances today. Sfc front stalled across the FA today. The front has settled further south that previous model runs indicated yesterday, with a southward shift of the best severe potential. Moderately strong impulse will kick out of WY/MT in the the afternoon and evening and will drive CI there. Storms may also fire along the Pine Ridge and INVOF of the front if capping can be overcome. Another location for CI will be northern BH if the inhibition is also overcome. Given progged ML CAPE of 1-2.5 KJ/KG, deep bulk layer shear of 35 to 45 knots (highest north of the sfc front), expect supercells to be possible with strong rotating updrafts, capable of producing large hail and damaging winds. Best chances for rotating storms will be along and north of the sfc front. Still a very small window for tornadoes with any storms near the sfc front, which will start shifting SW into SW SD this afternoon. Storms will carry across the region through the evening and overnight, possibly lingering into the morning Wed as elevated activity. More storms are possible Wed and Thur as sufficient LL moisture will be in place with weak stability and additional impulses. The best chances for storms will be across the western third Wed with chances expanding to the entire FA Thur. Upper ridge builds into the region this weekend, with dry and hot conds expected. Impressive temps of 35 to almost 40C at h85 with close to 6000 H5 heights over WY, will offer record to near record highs well into the 100s with 110 to 115 possible on portions of the Plains, esp Sunday and Monday. Ridge begins to breaks down across the Northern Plains the middle of next week, with storm chances returning as the active northern periphery of the ridge settles south.

AVIATION

(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 525 PM MDT Tue Jul 7 2026

Isolated to scattered, potentially severe, thunderstorms will continue to develop over northeast Wyoming and western South Dakota late this afternoon into evening before moving over much of western South Dakota into the overnight hours. Large hail, frequent lightning, and gusty/erratic winds can be expected with any stronger convective cores. Transient MVFR/IFR conditions also expected around any heavier precipitation cores. Conditions will begin to improve around 11z as storms diminish and move out of the region. Another round of storms will begin to develop over northeast Wyoming and western South Dakota starting around 08/18z and lasting through the remainder of the forecast period.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.